A convenience class for writing vector files to disk.
There are two possibilities how to use this class:
1. static call to QgsVectorFileWriter.writeAsVectorFormat(…) which saves the whole vector layer
2. create an instance of the class and issue calls to addFeature(…)

newFilename – QString pointer which will contain the new file name created (in case it is different to fileName).

symbologyExport – symbology to export

symbologyScale – scale of symbology

filterExtent – if not None, only features intersecting the extent will be saved (added in QGIS 2.4)

overrideGeometryType – set to a valid geometry type to override the default geometry type for the layer. This parameter
allows for conversion of geometryless tables to null geometries, etc (added in QGIS 2.14)

forceMulti – set to True to force creation of multi* geometries (added in QGIS 2.14)

includeZ – set to True to include z dimension in output. This option is only valid if overrideGeometryType is set. (added in QGIS 2.14)

newFilename – QString pointer which will contain the new file name created (in case it is different to fileName).

symbologyExport – symbology to export

symbologyScale – scale of symbology

filterExtent – if not None, only features intersecting the extent will be saved (added in QGIS 2.4)

overrideGeometryType – set to a valid geometry type to override the default geometry type for the layer. This parameter
allows for conversion of geometryless tables to null geometries, etc (added in QGIS 2.14)

forceMulti – set to True to force creation of multi* geometries (added in QGIS 2.14)

includeZ – set to True to include z dimension in output. This option is only valid if overrideGeometryType is set. (added in QGIS 2.14)